Tool-steel alloy.



UNITED STATES PATENT OFFICE.

RICHARD H. PATCH, OF PHILADELPHIA, AND RADCLYFFE FURNESS, OF JENKINTOWN,

PENNSYLVANIA, ASSIGNORS TO THE MIDVALE STEEL COMPANY, OF PHILADEL- PHIA, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

TOOL-STEEL ALLOY.

No Drawing.

To all whom it may concern:

Be it known that we, RICHARD H. PATCH and RADCLYFFE FURNEss, citizens of the United States, residing at, respectively, Philadelphia, county of Philadelphia, State of Pennsylvania, and Jenkintown, county of Montgomery, State of Pennsylvania, have invented a new and useful Improvement in Tool-Steel Alloys, of which the following is a full, clear, and exact description.

Our invention relates to the production of non-deforming tool steel particularly adapted for dies, taps, reamers, and cutting tools for lathes and planers.

The invention comprises an alloy of steel and chromium combined in certain proportions with carbon.

Following is a typical composition, and one which careful experiment has shown to give an excellent result: Carbon 1.35%, chromium'19.50%, iron 79.00%. The alloy should contain about 1 to 1.50 per cent. of carbon, although, for special uses, this may be raised to 2 per cent. carbon. The chromium should be kept within the range between 15 and 20 per cent.

In the manufacture of tool steel, it is not Specification of Letters Patent.

chromium about 19.5

Patented Dec. 5, 1916.

Application filed September 16, 1915. Serial No. 50,960.

chrome steel compositions is an immense increase in the life of the tool and the capacity to cut at substantially higher speeds.

Having now fully described our invention, what we claim and desire to protect by Letters Patent is:

1. A tool steel containing'between 15 and 20 per cent. of chromium and between 1 and 2 per cent. of carbon.

2. A tool steel containing the following ingredients in approximately the proportions specified: steel about 79 per cent; per cent. and carbon about 1.35 per cent.

In testimony of which invention, we have hereunto set our hands at Philadelphia, on this 14th day of September, 1915.

RICHARD H. PATCH. RADCLYFFE FURNESS. Witness:

JAMES J. RAHILLY. 

